Carol has only 20p and 10p coins in her purse she has three times as many 20p coins and 10p coins if Carol has ?4.20 altogether,
2 answers:
Suppose that Carol has x 10p coins in her purse. Since she has three times as many 20p coins as 10p coins, then she has 3x 20p coins in her purse.
x coins of 10p value $0.10x and 3x coins of 20p value $0.60x.
In total this amount of money is $(0.10x+0.60x)=$0.70x that is exactly $4.20. Thus, you get the equation
0.70x=4.20.
Solve it:
Carol has 6 coins of 10p and 3·6=18 coins of 20p.
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Answer:
The equation that represents the motion of the string is given by:
.....[1] where t represents the time in second.
Given that: A = 0.6 cm (distance above its resting position) , k = 1.8(damping constant) and frequency(f) = 105 cycles per second.
Substitute the given values in [1] we get;
or
(a)
The trigonometric function that models the motion of the string is given by:
(b)
Determine the amount of time t that it takes the string to be damped so that
Using graphing calculator for the equation
let x = t (time in sec)
Graph as shown below in the attachment:
we get:
the amount of time t that it takes the string to be damped so that is, 0.5 sec
